Device and method for automatic network detection and formation

ABSTRACT

A communication device includes a communication port including network interface circuitry; and a processor, and a non-transitory storage medium configured to store program instructions which, when executed by the processor cause the communication device to perform a network operation comprising: entering into a listening phase; and searching for and attempting to acquire a network.

TECHNICAL FIELD

The disclosed technology relates generally to communication systems, andmore particularly, some embodiments relate to automatic networkdetection and formation systems and methods for automatic powermanagement.

DESCRIPTION OF THE RELATED ART

Energy consumption of electronic devices continues to be an increasingconcern in the electronics industry. This is true in the commercial,consumer and military/DOD sectors. Accordingly, electronic devices arebeing designed to consume less power through the use of low energydemand components and automated power management (e.g., automated unitshut down and restart).

It is common place today for electronic devices to communicate with oneanother. One common way in which devices communicate is by forming anetwork that includes two or more devices. Devices within a network arecommonly referred to as nodes of the network. There are several waysthat devices can be organized to form a network. One such way is to forma MoCA network specified by the well-known industry standard called“MoCA” administered by the Multimedia over Coax Alliance. Such MoCAnetworks arc commonly established over the coaxial cables that arctypically used within homes and offices to distribute televisionsignals, such as cable television signals, satellite television signalsor direct broadcast video-terrestrial (DBV-T) signals. It is commontoday for homes and offices to be wired with coaxial cable havingconnectors conveniently located throughout the home or office. Each suchconnector allows a device to connect directly to each other device inthe home or office that is connected to the coaxial cable wiring.

MoCA networks allow devices to communicate with one another at highspeed over coaxial cabling using transmissions that arc modulated atdesignated frequencies. In accordance with MoCA, a device that wouldlike to become part of a MoCA network, first listens on each of theplurality of designated MoCA frequencies (i.e., attempts to receivesignals transmitted by another node of a preexisting MoCA network). I hedesignated frequencies are commonly referred to as MoCA channels. MoCAcapable devices typically can only listen to one channel at a time. Uponbeginning the process of attempting to join a MoCA network, the devicewill listen for a predetermined time to each MoCA channel, one at a timein an attempt to receive a beacon signal.

A beacon signal is defined by MoCA as a signal transmitted by aparticular MoCA network node, referred to as the network coordinator(NC). The beacon is designed to he easy for a new node attempting tojoin an existing MoCA network to acquire. The beacon is transmitted atregular intervals by the NC. Therefore, if a MoCA network already existson the coaxial cable to which a new device is connected, the new devicewill be able to acquire the beacon when it initially listens to the MoCAchannels.

If no MoCA network yet exists on the coaxial cable to which the newdevice is connected, then the new device will start sending out beaconsof its own in an attempt to form a new MoCA network. The new networkwill be formed by the new device and any other device that is alsoseeking to join a MoCA network on the same coaxial cable.

When a MoCA node initially powers tip, the node will typically startsending beacons over the last operating frequency (EOF) used by thatdevice. The IOF is the MoCA channel that the device used last tocommunicate with other MoCA devices over a MoCA network.

MoCA designates the timing used by a MoCA network to send these beaconsin an attempt to acquire or form a new network. This timing requiresthat a new node attempting to join a MoCA network listen for 40 secondsto each of the possible MoCA channels to determine whether a MoCAnetwork already exists. The new node will listen to each channel one ata time for 1.05 seconds and then tune to the next channel.

Typically, the node will listen to LOF first and then search the channelwith the lowest frequency. The node will then search the LOF again. Thenode will then step up in frequency one channel. The node then returnsto listen again to the LOF. This pattern of bouncing between the LOF andthe next higher channel will continue until reaching the channel withthe highest frequency. This pattern is then repeated in descending orderfrom the channel with the highest frequency to the channel with thelowest frequency with LOF searched in between each other channel. Thisprocess of stepping up and down one channel at a time continues for the40 second listening phase.

After 40 seconds, if no beacons are found, the new node will determinethat there is no existing network. Accordingly, the new node will takethe role of NC in an attempt to form a new MoCA network. Accordingly,the new node will execute at least 100 “Beacon Phase Cycles” (BPCs).Each BPC consists of a period having a duration randomly selected fromthe range of 0.1 to 1 second during which the new node listens to one ofthe MoCA channels, followed by 50 beacon cycles. The beacontransmissions sent during the beacon cycles arc sent on the same MoCAchannel (i.e., the LOF) with the assumption being that another new nodethat attempts to join the network will search each of the possiblechannels during its 40 second initial listening period and hear thebeacons that the beaconing node is transmitting.

Each beacon cycle is 10 milliseconds long and includes a short bursttransmission of the beacon followed by an admission control frame (ACT).The ACF is a period of time during which the new node will listen tohear whether another node has acquired the beacon previously sent. The50 beacon cycles are followed by another period that randomly variesfrom 0.1 second to 1.05 seconds during which the new node will listen tothe LOF MoCA channel in an attempt to form a MoCA network on the LOFchannel. The combination of the 50 beacon cycles followed by the 0.1 to1.05 second listening period constitute one BPC. A node that is has notyet formed a network will execute 100 such BPCs and then enter alistening phase for another 40 seconds during which the node will searcheach of the possible channels to see whether a new network has beenformed on one of those other channels. This process is repeated until anew network is either formed or found. However, a problem arises whentwo or more devices attempt to join a MoCA network at essentially thesame time, each having a different LOF. That is, if two or more MoCAenabled devices connected to the same coaxial cable are powered uptogether, each will listen for a beacon for 40 seconds. Since neither isyet sending any beacons, neither will know of the existence of theother. At the end of the 40 seconds, each will time out withoutacquiring a network beacon. Therefore, they will each start sendingbeacons on their respective LOF. This is not a problem if the two nodeshad the same LOF, since they will eventually hear each other. However,if the two nodes have different LOFs, then they will not hear eachother. At the end of the 100 BPCs, each node will enter the 40 secondlistening phase. However, since the amount of time during which each isexecuting the BPCs is essentially statistically the same, they will bothstart listening at essentially the same time and the chances of onehearing the other are very low. That is, the listening period withineach BPC is randomly determined to be between 0.1 and 1.0 seconds.Therefore, it is possible for there to be a different in the totalamount of time it takes each node to execute 100BPCs. However, since theduration of each BPC is random, the average amount of time over the 100BPCs, statistically, w ill be very close to equal. Therefore, the twonodes will be synchronized and miss each other for several hours beforethe synchronization of the two nodes is sufficient disrupted to allowone to be transmitting beacons while the other is listening on the LOFof the other. This is typically not a significant problem, but for thefact that each MoCA node that is searching for a MoCA network consumes asignificant amount of power.

BRIEF SUMMARY OF EMBODIMENTS

According to various embodiments of the disclosed technology automaticnetwork detection and formation can be provided. In some embodiments, acommunication device, may include: a housing; a communication portincluding network interface circuitry; and a processor within thehousing, and a non-transitory storage medium configured to store programinstructions which, when executed by the processor, cause thecommunication device to perform a network operation comprising: enterinto a listening phase; and search for and attempt to acquire a network.

The listening phase may be configured to last for a predetermined periodof time, w herein the predetermined time may be a time that is longenough to search for and acquire a network beacon for a given networkMAC protocol.

Acquiring a network beacon may include acquiring a beacon transmitted bya network coordinator of a communication network.

The search operation may be initiated on the last operating frequencyused by the communication device to communicate over a communicationnetwork. The search operation may further include stepping through thechannels available for the communication device and conductingcommunications in accordance with the network protocol. The searchoperation may he initiated on the last operating frequency (LOF) used bythe communication device to communicate over a communication network andthe communication device may be configured to step through the channelsone at a time, for example, starting from the LOF.

The search operation may be initiated on the last operating frequency(LOF) used by the communication device to communicate over acommunication network: and the search operation continues by searchingthe channels one at a time from the lowest frequency to the highestfrequency and returning to search the LOL between each search of theindividual frequencies from the lowest frequency to the highestfrequency.

The network operation may further include initiating a beacon phase ifthe communication device does not find a network during the searchoperation. The beacon phase may include transmitting beacons over thenetwork and listening for beacons that may be transmitted by anothernode. The beacon phase may further include repeating the listening phaseif a beacon from a network node is not received by the communicationdevice during the beacon phase. The beacon phase may also includelistening for a response from a network node to the beacons transmittedby the communication device. The listening phase may be repeated if aresponse to a beacon is not received by the communication device duringthe beacon phase.

The listening phase may be conducted for an amount of time that isrequired to search each channel at least once. The listening phase maybe of any duration, but in one embodiment is configured to be of aduration varying between 0.1 seconds and 1 second.

In yet another embodiment, a method of network formation performed by acommunication device, includes: the communication device entering alistening phase during which the communication device listens on apredetermined channel to determine whether a network has been formed;and if the communication device does not detect a network during thelistening phase, the communication device entering a beacon phase duringwhich the communication device transmits beacons of a type compatiblewith a network protocol and listens for either beacons from anothernetwork node or a response to the beacons transmitted by thecommunication device.

In some embodiments if a beacon or a response to a beacon transmitted bythe communication device is not received by the communication deviceduring the beacon phase, the communication device may be configured toreturn to the listening phase.

The listening phase may be configured to last for a predetermined periodof time, wherein the predetermined time is a time that is long enough tosearch for and acquire a beacon for a given network MAC protocol. Thelistening phase may be initiated on the last operating frequency used bythe communication device to communicate over a communication network.The listening phase may include stepping through the channels availablefor the communication device and conducting communications in accordancewith the network protocol.

The listening phase may be initiated on the last operating frequency(LOF) used by the communication device to communicate over acommunication network and the communication device steps through thechannels one at a time starting from the LOF. In further embodiments,the listening phase may be initiated on the last operating frequency(LOF) used by the communication device to communicate over acommunication network; and the search operation continues by searchingthe channels one at a time from the lowest frequency to the highestfrequency and returning to search the LOL between each search of theindividual frequencies from the lowest frequency to the highestfrequency.

The listening phase may be conducted for an amount of time that isrequired to search each channel at least once. Although any duration canbe selected depending on the application, in one embodiment thelistening phase is of a duration varying between 0.1 seconds and 1second.

Other features and aspects of the disclosed technology will becomeapparent from the following detailed description, taken in conjunctionwith the accompanying drawings, which illustrate, by way of example, thefeatures in accordance with embodiments of the disclosed technology. Thesummary is not intended to limit the scope of any inventions describedherein, which are defined solely by the claims attached hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

The technology disclosed herein, in accordance with one or more variousembodiments, is described in detail with reference to the followingfigures. The drawings are provided for purposes of illustration only andmerely depict typical or example embodiments of the disclosedtechnology. These drawings are provided to facilitate the reader'sunderstanding of the disclosed technology and shall not be consideredlimiting of the breadth, scope, or applicability thereof. It should benoted that for clarity and ease of illustration these drawings arc notnecessarily made to scale.

FIG. 1 is a diagram illustrating an example of a multimedia network withwhich various embodiments of the technology disclosed herein may beimplemented.

FIG. 2 is a diagram illustrating an example architecture for acommunication module having power management capabilities in accordancewith one embodiment of the technology disclosed herein.

FIG. 3 is a diagram illustrating an example of a communication devicewith which the technology disclosed herein may be implemented.

FIG. 4 is a diagram illustrating another example of a communicationdevice in accordance with one embodiment of the technology disclosedherein.

FIG. 5 is an operational flow diagram illustrating an example processfor power management based the absence or presence of a connection inaccordance with one embodiment of the technology disclosed herein.

FIG. 6 is an operational flow diagram illustrating another exampleprocess for power management based the absence or presence of theconnection in accordance with one embodiment of the technology disclosedherein.

FIG. 7 is an operational flow diagram illustrating an example processfor network formation in accordance with one embodiment of thetechnology disclosed herein.

FIG. 8 is a diagram illustrating an example of the timing of a BeaconPhase performed by a network node during network acquisition inaccordance with one embodiment of the technology disclosed herein.

FIG. 9 illustrates an example computing module that may he used inimplementing various features of embodiments of the disclosedtechnology.

The figures are not intended to he exhaustive or to limit the inventionto the precise form disclosed. It should be understood that theinvention can be practiced with modification and alteration, and thatthe disclosed technology be limited only by the claims and theequivalents thereof.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the technology disclosed herein are directed towarddevices and methods for providing power management for communicationdevices based on the status of a device's connection. More particularly,the various embodiments of the technology disclosed herein relate topower management based on the presence or absence of a physicalconnection to the device, or based on the presence or absence of anetwork attached to the device. Further embodiments are related towardautomatic network detection and formation.

Before describing the disclosed systems and methods in detail, it isuseful to describe an example of an environment in which the disclosedtechnology can be implemented. The example network of FIG. 1 is nowdescribed for this purpose. The network of FIG. 1 is one example of amultimedia network implemented in a home or office. In this example, awired communications medium 100 is shown. The wired communicationsmedium might be a coaxial cable system, a power line system, a fiberoptic cable system, an Ethernet cable system, or other similarcommunications medium. Alternatively, the communications medium might bea wireless transmission system. As one example of a wired communicationmedium, with a Multimedia over Coax Alliance (MoCA®) network, thecommunications medium 100 is coaxial cabling deployed within a residence101 or other environment. The systems and methods described herein areoften discussed in terms of this example coaxial network application,however, after reading this description, one of ordinary skill in theart w ill understand how these systems and methods can lie implementedin alternative network applications as well as in environments otherthan the home.

The example network of FIG. 1 comprises a plurality of network nodes102, 103, 104, 105, 106 in communication according to a communicationsprotocol. For example, the communications protocol might conform to anetworking standard, such as the well-known MoCA standard. Nodes in sucha network can be associated with a variety of devices. For example, in asystem deployed in a residence 101, a node may be a networkcommunications module associated with one of the computers 109 or 110.Such nodes allow the computers 109. 110 to communicate on thecommunications medium 100. Alternatively, a node may be a moduleassociated with a television 111 to allow the television to receive anddisplay media streamed from one or more other network nodes. A nodemight also be associated with a speaker or other media playing devicesthat plays music. A node might also be associated with a moduleconfigured to interface with an internet or cable service provider 112,for example to provide Internet access, digital video recordingcapabilities, media streaming functions, or network management servicesto the residence 101. Also, televisions 107, set-top boxes 108 and otherdevices may be configured to include sufficient functionality integratedtherein to communicate directly with the network.

With the many continued advancements in communications technology, moreand more devices are being introduced in both the consumer andcommercial sectors with advanced communications capabilities. Many ofthese devices are equipped with communication modules that cancommunicate over the wired network (e.g., over a MoCA Coaxial Network)as well as modules that can communicate over fiber or other networks aswell. Indeed, in many environments, it is becoming more commonplace forthere to be multiple networks, and sometimes multiple differentnetworks, across which a user may wish the network devices tocommunicate. In such circumstances, network bridges can be used to allowdevices to communicate across multiple networks.

Having thus described an example environment in which the disclosedtechnology can be implemented, various features and embodiments of thedisclosed technology are now described in further detail. Descriptionmay be provided in terms of this example environment for ease ofdiscussion and understanding. After reading the description herein, itwill become apparent to one of ordinary skill in the art that thedisclosed technology can be implemented in any of a number of differentcommunication environments (including wired or wireless communicationenvironments) operating with any of a number of different electronicdevices, whether or not according to various similar or alternativeprotocols or specifications.

As noted above, some embodiments of the technology disclosed herein maybe implemented to conduct power management operations based on thepresence or absence of a communication cable connected to the subjectequipment. FIG. 2 is a diagram illustrating an example architecture fora communication module having power management capabilities inaccordance with one embodiment of the technology disclosed herein. Inthe example illustrated in FIG. 2, the communication device 204 includespower management module 208 and device functional modules 214. Powermanagement module 208 includes a sensing module 210 and a power controlmodulo 212. Sensing module 210 can include the capability detect thepresence or absence of a cable connected to the communication device204. In other embodiments, sensing module 210 can include the capabilityto detect the presence or absence of a signal on incoming signal path.

Device functional modules 214 can include, for example, one or moreelectronic components (with or without associated software) used bycommunication device 204 in its intended operation. For example, wherecommunication device 204 is a set-top box, device functional modules 214can include, for example, a communications transceiver, including atransmitter and receiver to transmit and receive data (e.g., MoCApackets) across a coaxial network, tuners, a display, display drivers,indicators, GUI generators, DVRs, and the like. Communication device 204is not limited to set-top box applications it can also be applied toadapters, bridges, routers, and other equipment with networking orcommunications capabilities.

In the illustrated example, communication device 204 includes a portthat may include a signal path 215 connected to a connector 216 such as,for example, an F connector or the like. Signal path may include, forexample, a conductive wire (whether or not shielded), traces on aprinted circuit board, or other electrical connection between connector216 and the device components. As illustrated, connector 216 may beconfigured to be connected to a physical communication medium 218 suchas, for example, a coaxial cable (e.g., via a mating connector), whichin turn may he connected to a wall outlet 220. Wall outlet 220 mayconnect to a coaxial network or backbone such as, for example,communications medium 100 as shown in the example of FIG. 1. As willbecome apparent to one of ordinary skill in the art after reading thisdescription, the disclosed technology can be implemented with a numberof different communication interfaces, and it is not limited toimplementation with the exemplary F connector and coaxial cable.

Communication device 204 can further include a housing within which someor all of its components can be mounted (partially or completely).Interface components such as displays, indicators and connectors can bemounted at an exterior surface of the housing so that they can be viewedor accessed easily. A power supply is typically included with thecommunication device 204. The power supply can include, any of a varietyof power sources such as, for example, batteries or capacitor banks (orother energy storage devices), AC/DC power converters (or other powerconverters or inverters, whether AC-to-DC, AC-to-AC, DC-to-DC orDC-to-AC), generators, photovoltaic cells, and so on. The power supply(whether or not including related voltage dividers, conditioningcircuits etc.) can be used to supply power to the various components andmodules. Accordingly, the various components and modules may be coupledto draw energy directly or indirectly from the power supply.

Having thus presented an example architecture for a communication device204, an example of its operation is now described in terms of thisexample architecture. In operation, sensing module 210 can beimplemented to detect the presence or absence of a cable 218 connectedto connector 216. Sensing module 210 may be configured to communicatethe result of this detection to power control module 212. For example,where sensing module 210 detects the absence of cable 218. Itcommunicates this information to power control module 212.

Upon receipt of this information, power control module 212 may beconfigured to transition the communication device 204 into a sleep mode.That is power control module 212 can be configured to reduce power ofcommunication device 204 to save energy. In various embodiments, one ormore components of communication device 204 can be powered down ortransitioned to a low-power state to reduce the overall power consumedby the unit. A low-power state can comprise a state in which thecomponent consumes less power than it it were to remain in its normaloperational state. Power control module 212 may be configured to reducepower of the device in accordance with a predetermined methodology.However, in other embodiments, power control module 212 may beconfigured to determine a number of power-down factors such as, forexample, which of a plurality of components to power down, the degree orextent to which such selected components should be powered down, thelength of time for which the components should be powered down (or in areduced-power state) and so on. Such determinations can be made, forexample, based on the functions performed by communication device 204,components related to those functions and other factors. As a furtherexample. Energy Star requirements may dictate the extent to which one ormore components of the communication device 204 are powered down.

Determinations can also be made based on the amount of time required toreturn communication device 204 to an operational state upon power up,and the speed with which this must occur based on the communicationrequirements or specifications of the communication device 204. Forexample, if communication device 204 is part of a high-prioritycommunication system in which delay or latency cannot be tolerated,components that take an unduly long time to power back up (e.g., longerthan the amount of time that would be permitted to allow thecommunication device 204 to return to operation and meet a givenspecification) might not be powered down, or might only be partiallypowered down (so that they don't take as long to return to theiroperational state). This determination can be preconfigured for a givendevice or application, or may be determined on a case-by-case basis bythe unit depending on the application of the unit, the importance orpriority of a given communication flow with which it is operating, andso on.

Power control module 212 may further he configured to limit the amountof time that the unit or portions thereof are in power-down mode, l orexample, the system may be configured to enter a power-down or sleepmode, yet continue to operate sensing module 210 to continue to sensefor a connection. When the connection returns (whether a physicalconnection, signal, or other indicia of returning service, depending onthe embodiment) this can be communicated to power control module 212,which can, in turn, begin to return the device functional modules 214 tothe on state. In other embodiments, a timer can be set and configuredsuch that regardless of the absence or presence of the connection, theunit is powered back up to its fully operational mode (or partiallyoperational in some embodiments, depending on the application) when thepredetermined amount of time has elapsed. In further embodiments,sensing module 210 may be configured to sense continuously or regularlyupon the initiation of the power-down mode, while in other embodiments,sensing module 210 may be configured to also enter a sleep mode(partially or fully power down) for a predetermined period of time upondetecting the absence of the connection.

In addition to or instead of checking for the presence of a cable orother physical connection, embodiments may also be implemented in whichsensing module 210 is configured to detect the presence or absence of anetwork service on a communication link. For example, sensing module 210can be configured to look for the absence or presence of a signal at thecommunications interface (whether wired or wireless), which informationcan be used to trigger the power-savings mode. Various techniques can beused to detect the absence or presence of a network service, examples ofwhich are described in further detail below.

There are a number of techniques that can be used to determine thepresence or absence of a connection in accordance with variousembodiments. For example, where sensing module 210 is configured todetermine whether a cable is connected to the device, it can beconfigured to measure signal characteristics on signal path 215 (whichmay itself indicate whether a cable is connected to the device). As afurther example, in one embodiment, the system can be configured tosimply detect the presence or absence of a signal on signal path 215. Infurther embodiments, the system can be configured to check forparticular signal characteristics of a signal that may be present on thesignal path. That is, in some embodiments, the system can be configuredto check for particular network communications (e.g., the presence ofnetwork beacons) on signal path 215.

The system may also be configured to launch a probe signal onto signalpath 215 and detect and measure the results of that launched signal.Such a probe signal may be launched, for example, by sensing module 210,or by one of the device functional modules 214. Cable presence circuitscan be included with sensing module 210 to determine whether the cableis connected or not by, for example, measuring the resulting voltage orcurrent at the port due to the test signal, comparing the measured valuewith a reference value and, based on the outcome of the comparison,deciding whether an external cable is mated to the device or not. Forexample, signal characteristics can be measured at the center pin orsensed at a filter connected as part of signal path 215. As a furtherexample, the phase or amplitude, or both, of the signal may be measuredto determine whether a cable 218 (and ultimately the network) isconnected to connector 216.

In various embodiments, the reference values may be trained bycharacterization and stored, or the reference values may be configuredby design of the unit. For example, the communication device 204 may becharacterized during design to establish a characterization of the phaseand amplitude of a launched signal for connected and openedconfigurations.

In some embodiments, the test signal may include a signal that is sweptover a frequency range such that measured results can he compared totheir corresponding references at various frequencies. For example, thesystem can be configured to compare the energy at one or morefrequencies with reference energy values corresponding to thosefrequencies to determine whether a cable is present.

In further embodiments, the test signal can be configured to be alow-level signal or of short duration to minimize the potentialinterference that may be induced on signal path 215 (and potentiallyonto the network) in the event that the cable is connected. For example,the system may be configured to intermittently launch a short durationsignal to detect the presence or absence of a connection, and then waitfor a predetermined period of time before launching another signal. Itis noted that there may be a trade-off between recovery time and thesampling period. For example, if a fast recovery is needed based onsystem requirements, the system may be configured to sample or probemore frequently.

FIG. 3 is a diagram illustrating an example of a piece of acommunications module with which the technology disclosed herein may beimplemented. After reading this description, one of ordinary skill inthe art will appreciate that the technology disclosed herein can be usedwith any of a number of different devices or equipment havingcommunication capabilities.

With reference now to FIG. 3, in this example application, the examplecommunication device 204 includes sensing module 210, powder controlmodule 212, and one or more device functional modules 214. In thisexample, device functional modules 214 include an I/O interface module308, functional modules 338, a control module 336, and a communicationmodule 334. Communication device 204 also includes a processor 306(which can include multiple processors or processing units), and memory310 (which can include memory units or modules of different types).Processor 306 in memory 310 can also be shared by sensing module 210 andpower control module 212, or these components can include their ownprocessors and memory. The various components of the communicationdevice 204 are communicatively coupled via a bus 312 over which thesemodules may exchange and share information and other data.

I/O interface module 308, as provided in the illustrated example, can beconfigured to couple communication device 204 to other network nodes.These can include other network nodes or other equipment. In someembodiments, I/O interface module 308 comprises network interfacecircuitry, which in this example architecture includes a receiver module318 and a transmitter module 320. These can, for example, include acommunication receiver and a communication transmitter for wired orwireless communications across the network. Accordingly, communicationsvia the I/O interface module 308 can, for example, be wired networkcommunications, and the transmitter and receiver contained therein caninclude line drivers and receivers, as may be appropriate for thenetwork communication interfaces, for example. I/O interface module 308can be configured to interface with a network such as a MoCA network oran Ethernet network (although other network interfaces can be provided)or with a non-network physical connection. I/O interface module can alsobe configured to provide a wireless communication interface (e.g.,Bluetooth, Zigbee, IEEE 802.11, and so on) including an antenna orantennas. Transmitter module 320 may be configured to transmit signalsthat can include data, beaconing and other MAC communications, and otherinformation. These may be sent using a standard network protocol ifdesired. Receiver module 318 is configured to receive signals from otherequipment. These signals can likewise include data and othercommunications from the other equipment, and can also be received in astandard network protocol if desired.

Memory 310 can be made up of one or more modules of one or moredifferent types of memory, and in the illustrated example is configuredto store data and other information 324 as well as operationalinstructions that may be used by the processor to operate communicationdevice 204. The processor 306, which can be implemented as one or morecores, CPUs, DSPs, or other processor units, for example, is configuredto execute instructions or routines and to use the data and informationin memory 310 in conjunction with the instructions to control theoperation of the communication device 204, for example, in the case of aset-top box program guides or other GUIs can be stored in memory 310 andused in the operation of communication device 204.

Other modules can also be provided with the communication device 204depending on the equipment's intended function or purpose. A completelist of various additional components and modules would be too lengthyto include, however a few examples are illustrative, l or example, aseparate communication module 334 can also be provided for the equipmentto manage and control communications received from other entities, andto direct received communications as appropriate. Communication module334 can be configured to manage communication of various informationsent to and received from other entities. Communication module 334 canbe configured to manage both wired and wireless communications. Aseparate control module 336 can be included to control the operation ofcommunication device 204. For example, control module 336 can beconfigured to implement the features and functionality of communicationdevice 204. Functional modules 338 can also be included to provide otherequipment functionality. For example, in the case of a set-top box,these modules (which may include various forms of hardware and software)can be provided to receive program content, decode received programcontent, convert the decoded content to an acceptable form for playback,and so on. As these examples illustrate, one of ordinary skill in theart will appreciate how other modules and components can he includedwith communication device 204 depending on the purpose or objectives ofthe equipment.

FIG. 4 is a diagram illustrating another example of a communicationdevice in accordance with one embodiment of the technology disclosedherein. The example in FIG. 4 includes a network node 400 connected to aset-top box 412. In the example illustrated in FIG. 4, the node 400 is aMoCA node that includes a physical layer (PHY layer) 403, and a mediaaccess control layer (MAC layer) 406. In other embodiments, node 400 canbe a network node for other networks including a WiFi network (IEEE802.11) or other local area or wide area network.

PHY layer 403 can be included with network node 400 to providecommunications over a communications medium such as, for example, acoaxial cable 404 (used as the medium for a MoCA network), an Ethernetcable, a wireless interface, and so on. PHY layer 403 can be used toprovide modulation and demodulation of signals for transmission over thecommunications medium. As illustrated PHY layer 403 is communicativelycoupled to MAC layer 406. MAC layer 406 can be used to determine thecontent and timing of transmissions over the communication network(e.g., the MoCA network). In the illustrated example, MAC layer 106includes a processor 408 and a memory 410. In various embodiments,processor 408 is responsible for performing the functions of MAC layer406 and communicates with memory 410 to both retrieve instructions forexecution of the processor functions, and also to store informationnecessary to the functions of the processor 408.

In the illustrated example, node 400 is coupled to a device, such as aset top box 412. The node 400 can be configured to allow the set-top box412 to communicate with other network nodes such as, for example, otherset-top boxes, DVR's, computers, and so on, over the network. In otherembodiments, node 400 can be included within set-top box 412, or withinanother network device. Accordingly, MAC layer functionality can beperformed by a processor that also performs a set-top box functions.Alternatively, set-top box functions and MAC layer functions can beperformed by independent processors. In terms of the example illustratedin FIG. 3, the functionality of both network node 400 and set-top box412 can be included in communication device 204.

As noted above, the timing and content of the signals are generated andcontrolled by MAC layer 406. The signals transmitted over the networkare generated by the PHY layer 403. One of ordinary skill in the artwill typically understand the division of functionality between a PHYlayer 403 and in MAC layer 406.

As described above, in various embodiments, a communication device (e.g.communication device 204) can be provided with features andfunctionality to perform power management operations based on thedevice's connectivity with a network or other communications interface.FIG. 5 is an operational flow diagram illustrating an example processfor power management based the absence or presence of a connection inaccordance with one embodiment of the technology disclosed herein. FIG.6 is an operational flow diagram illustrating another example processfor power management based the absence or presence of the connection inaccordance with one embodiment of the technology disclosed herein.Particularly, the FIG. 5 illustrates an example of managing power basedon the absence or presence of port connectivity, while FIG. 6illustrates an example of managing power based on the absence orpresence of a communication network. FIGS. 5 and 6 are now described interms of the example communication device 204 introduced above. Afterreading this description, one of ordinary skill in the art willunderstand how these processes can be implemented with othercommunication devices.

Referring now to FIG. 5, at operation 502, the device is configured toprobe a communication port. For example, sensing module 210 can probethe communication port associated with connector 216 to determinewhether a mating connector/cable is connected to connector 216, or todetermine whether a signal is present. At operation 506, the devicedetermines whether there is a connection. At this step, the device(e.g., sensing module 210) can be configured in any of a number ofdifferent embodiments to determine, for example, whether a cable ornetwork is connected to the port or whether the appropriate signal ispresent at the port.

If there is no connection, and the system is not yet powered down, thesystem initiates power-down operations to power down, or reduce thepower of, selected components. This is illustrated at operations 509 and512. If the system was already in a powered-down mode, this powered-downmode is maintained at operation 512.

At operation 515 the system can continue monitoring the port todetermine whether a connection is established as illustrated byoperation 515. The monitoring can be performed on a periodic basis asnoted above. At this point, power management components (e.g. sensingmodule 210 and power control module 212) may remain awake. In otherembodiments, power management components (e.g. sensing module 210 andpower control module 212) may be powered down along with the functionalmodules of the communication device. If the presence sensing components(e.g. sensing module 210 of power management module 208) are powereddown, at the next probing event they arc powered back on for sensing. Ifduring further probing iterations the connection continues to be absent,the device remains in the powered down mode, but can continue periodicmonitoring. The sensing modules may be configured to periodically awakenfrom the sleep mode at least long enough to determine whether anexternal cable is mated to the connector, or whether the port isotherwise connected. Accordingly, in embodiments where the sensingmodules are powered down as well, the sensing modules can he toggledbetween a sensing mode and a sleep mode to conserve power when notchecking the connection.

If the system is currently powered, and the device determines that thereis a connection (operations 506, 509), power is maintained. If on theother hand, the system is in a powered-down mode and the devicedetermines at operation 506 that there is a connection, power isrestored to the affected components. This is illustrated by operations509 and 522. In some embodiments, the operational status of the devicecan be confirmed to determine whether power should be maintained at theaffected components. Accordingly, at operation 525, the device can beconfigured to initiate an acquisition process or otherwise attempt toconnect to the network (or other communication link at the port). If theacquisition is successful or the device is otherwise confirmedoperational as illustrated at 527, power is maintained as illustrated atoperation 530. The powered device can continue monitoring forconnections to determine whether power should be maintained or powereddown. This is illustrated by operation 532.

On the other hand, if at operation 527 the acquisition is not successfulor the device is not otherwise confirmed operational, the device may bereturned to a powered-down mode and monitoring continued. This isillustrated by operational flow path 528, and operations 512 and 515.

Referring now to FIG. 6, an example method for checking for a connectionbased on network detection is now described. At operation 632, in thisexample the device wakes from a sleep mode, or low-power mode and entersa search mode to search for the presence of a network. In the sleep modeor low-power mode, the device may be powered down or in a mode withpower consumption reduced or minimized. In the search mode, power isreturned to the device so it can search for the presence of a networkand one or more communication interfaces. In various embodiments,different levels of power may be applied to the device in the searchmode. For example, in some embodiments, only those components necessaryfor searching (e.g. power management module 208 or sensing module 210)are powered on during search mode, while in other embodiments additionalcomponents or even the entire device are powered on in the search mode.

At operation 634, while in the search mode, the device searches for thepresence of a recognizable network. In some embodiments, this can bedone, for example, by a sensing module 210. The device may be configuredto search for network signals in general, or it may be configured tosearch for particular signals or data packets conforming to one or moreof a plurality of acceptable network protocols. For example, in someembodiments, the system can be configured to search for particular MACprotocol elements the presence of which would indicate the existence ofa network. In terms of a MoCA network, for example, the system can beconfigured to listen for a beacon, which would indicate that there is anetwork present. A beacon in the MoCA context is a signal transmitted bya particular MoCA network node, referred to as the network coordinator(NC). The system can be configured to listen for a predetermined time(e.g., for a few beacon cycles during a listening period), and canfurther be configured to do so for each MoCA channel, one at a time. Forexample, the system can be configured to listen throughout the searchmode or at given times (e.g., beginning middle or end) of the searchmode. The system may further be configured to listen for a short timethat is long enough to detect a beacon preamble.

For example, consider the case of the MoCA network in which 50 beaconsare sent over a 500 ms period. Sampling for approximately 100 ps attimes spread out over the listening period enables the system to detectat least one beacon preamble over the 500 ms period. Examples of thisare discussed in more detail below with reference to FIGS. 7 and 8.

If a network is detected, power is applied to system components andnetwork operations are initiated. This is illustrated by operation 637,652 and 654. In some embodiments, the entire communication device ispowered up for operation, while in other embodiments, only thosecomponents necessary for communication across the detected network arepowered unless and until other device operations are required. Duringoperation, the communication device can be configured to determinewhether operations have ceased and whether it should enter a sleep modebased on network communication requirements. If network communicationsare continuing, power is maintained and the device continues operate.This is illustrated by operation 656, and 658.

Once network operations have ceased, the system can be configured toreturn to the sleep mode by powering down system components asillustrated by operational flow line 650 and operation 642. At operation642, the system can be configured to power down the system componentsused for network operations and either return to the search modedirectly (not shown in FIG. 6), or wait for a predetermined period oftime before returning to the search mode (operations 644, 646 and 648).In embodiments where the communication device returns to the search modedirectly, power management module 208 (or power control module 212) canremain operational to determine whether a network is present while theremainder of the device is in sleep mode. In an embodiment where thedevice waits before returning to the search mode, the power managementmodule can also return to the sleep mode (although it docs not have to)as well as the remainder of the communication device. An example of thisis illustrated by operations 644. 646, and 648 in which a timer is setand allowed to elapse before returning the communication device to thesearch mode.

If at operations 634 and 637 no network is detected, the system may bereturned to a sleep state for a period of time and then again returnedto the search mode to search for the presence of a network. This isillustrated by operations 642, 644, 646, and 648. In this manner, thedevice can be configured to toggled between a low-power mode and asearch mode to search for the presence of a network.

In further embodiments of the systems and methods disclosed herein acommunication device can be configured to form a new network with one ormore other devices. FIG. 7 is an operational flow diagram illustratingan example process for network formation in accordance with oneembodiment of the technology disclosed herein. In accordance with thisexample process, when the device is powered on it enters into alistening phase. This is illustrated by operation 701 and 703. Thelistening phase can be configured to last for a predetermined period oftime, which preferably is enough time to search for and acquire abeacon. For example, in one embodiment, the listening phase can beconfigured to last for 40 seconds, although other time periods arepossible.

During the listening phase, the communication device (e.g. network node400) searches for and attempts to acquire a beacon. The node 400, forexample, may begin the search on the last operating frequency (LOF) usedby the node 400 to communicate over a network. The LOF is a channeldefined by the network specification. Typically, as part of the networkprotocol, a network specification will define several channels overwhich nodes can communicate with one another (e.g., determine thefrequency and other characteristics associated with channel). Forexample, a MoCA network is defined by the MoCA specification publishedby the Multimedia over Coax Alliance (MoCA). Several channels aredefined by the MoCA specification for use by MoCA nodes. The particulargroup of channels that are used by a particular MoCA network may dependupon whether the coaxial cabling over which the MoCA nodes arccommunicating is also being used to distribute cable television contentor satellite television content.

After initiating the search on the LOF, the node 400 steps through thechannels available for that node 400 and communicates in accordance withthe network protocol. In one embodiment of the disclosed technology, thenode steps through the channels one at a time starting from the LOF.Alter searching the LOF, the node 400 searches the channel with thelowest frequency. The node 400 and then returns to search the LOF again.Next, the node 400 searches the next higher frequency. This pattern ofbouncing from the LOF to the next higher channel continues until thechannel with the highest frequency has been searched. At that point, thenode 400 will continue the search pattern from the channel with thehighest frequency to channel with the lowest frequency, searching theLOF in between each other channel. This search pattern will continueuntil the node has exhausted the 40 second listening phase or a networkis found. This is illustrated by operation 705.

If node 400 finds another network (i.e., can acquire a beacontransmitted by a network coordinator (NC) of another network), then atoperation 707, node 400 exits the network acquisition process. However,if the node 400 does not find another network, then node 400 begins aBeacon Phase (BP) as illustrated by operation 700. During the BP, node400 transmits beacons over the network, as well as listens for beaconsbeing transmitted by another node. If another node is present on thesame channel, then that node will receive the beacon and respond, ornode 400 hears beacons from the other node. In either case, node 400will have found another node (operation 711). Alternatively, if node 400cannot find another node on the same channel and no other node detectsnode 400 (operation 711), then the node 400 returns to operation 703 andonce again starts a listening phase to search for a network (e.g., onall of the available channels in the network).

The duration of the listening phase can he selected to be any durationbetween the minimum and maximum duration allowed by the networkspecification. In accordance with one embodiment of the disclosedtechnology, the duration of the listening phase is determined randomly.That is, the listening time can vary from one cycle to the next so thatit is not the same amount of time each cycle. The variations can bepredetermined based on anticipated performance of the MAC parameters ofthe network. In one embodiment, the minimum duration is the amount oftime required to search each channel at least once. The maximum durationmay be determined as a trade-off between longer times for nodes to findone another if neither is yet part of a network and greater likelihoodthat a node will find a network that exists. That is, the more time anode remains in listening phase, the more likely it will be to find anexisting network. However, the less time a node remains in listeningphase, the more likely it w ill be to transmit a beacon to another nodethat is searching for an existing network. Using a random or a varyingperiod of time for the listening phase listening phase provides amechanism for offsetting the times when one node is transmitting beaconsand another node is in listening mode.

Although this technique can be used for any of a number of differentnetworks, an example in the context of one particular network can beuseful to illustrate the timing. FIG. 8 is a diagram illustrating anexample of the timing of a Beacon Phase (BP) performed by a network node400 during network acquisition in accordance with one embodiment of thetechnology disclosed herein. The BP in this example comprises a randomnumber of beacon phase cycles 801. FIG. 8 illustrates two such beaconphase cycles 801A, 801B. Each beacon phase cycle comprises a firstlistening period 803 during which node 400 listens to the LOF channel todetect any other nodes that might be active on the channel. Inaccordance with one embodiment of the disclosed technology, thelistening period 803 has a duration that is variable between 0.1 secondsand 1 second. The particular duration of the listening period 803 israndomly determined within this range. This can vary from cycle to cycleaccording to a predetermined algorithm.

In one embodiment, node 400 listens during the entire listening period803. Alternatively, node 400 only listens for a limited number of beaconcycles, each of which in this example embodiment is 10 millisecondslong. In accordance with one such embodiment, node 400 listens a secondtime for another limited number of beacon cycles if the listening periodis greater than 0.5 second. The particular number of beacon cycles thatthe node listens over the duration of the listening period can varydepending on the implementation.

In addition to the listening period 803, each beacon phase cycle alsocomprises a plurality of beacon cycles 805. In one embodiment of thedisclosed technology, listening period 803 is a time such that the firstof the beacon cycles 805 begins immediately after the end of thelistening period 803. In one embodiment, there are 50 beacon cycles,each 10 milliseconds in duration. During each beacon cycle 805, a beacon807 is transmitted followed by an admission control frame (ACF) 800. Itshould be noted that the scale of the timing diagram is not necessarilyindicative of the duration of the beacon 807 and the ACF 800.

After 10 ms, a second beacon cycle 811 starts. The beacon phase cycle801A ends when all beacon cycles concluded (50 in the illustratedexample). During the ACF 809, node 400 listens to determine whetheranother node has heard the beacon that node 400 sent. If so, then node400 has found another node (e.g., operation 711). Node 400 may then exitthe process (e.g., operation 707).

In accordance with one embodiment of the disclosed technology, thenumber of beacon phase cycles 801 is randomly selected from a range of Nto M, where N is the minimum number of beacon phase cycles 801 and M isthe maximum number of beacon phase cycles 801. In one embodiment, theminimum N is equal to 100. In some cases, the network specification maydetermine the value of the minimum. In one such embodiment, the maximumnumber M may be set to 200. Therefore, the number of beacon phase cycles801 within one BP is randomly selected to be a value from 100-200.

In one embodiment, the value of M may be configured to depend upon theLOF of node 400. If the LOF of the node is near the channel at whichnode 400 begins to search, then the value of M can be reduced. However,if the LOF is further from the channel that node 400 begins searching,then the value of M is increased. It should be noted that the number ofbeacon phase cycles 801 is random, no matter what the values of N and M,but that the range of value from which the number is selected will varywith N and M.

By making the number of beacon phase cycles 801 random, nodes that havedifferent LOFs and that power up at approximately the same time willfind each other more rapidly, since the random number of beacon phasecycles 801 will change the timing of one node with respect to the otherand put them out of synchronization with one another.

As used herein, the term module might describe a given unit offunctionality that can be performed in accordance with one or moreembodiments of the technology disclosed herein. As used herein, a modulemight be implemented utilizing any form of hardware, software, or acombination thereof. For example, one or more processors, controllers,ASICs, PLAs, PALs, CPLDs, FPGAs, logical components, software routinesor other mechanisms might be implemented to make up a module. Inimplementation, the various modules described herein might beimplemented as discrete modules or the functions and features describedcan be shared in part or in total among one or more modules. In otherwords, as would be apparent to one of ordinary skill in the art afterreading this description, the various features and functionalitydescribed herein may be implemented in any given application and can beimplemented in one or more separate or shared modules in variouscombinations and permutations. Even though various features or elementsof functionality may be individually described or claimed as separatemodules, one of ordinary skill in the art will understand that thesefeatures and functionality can be shared among one or more commonsoftware and hardware elements, and such description shall not requireor imply that separate hardware or software components arc used toimplement such features or functionality.

Where components or modules of the technology are implemented in wholeor in part using software, in one embodiment, these software elementscan be implemented to operate with a computing or processing modulecapable of carrying out the functionality described with respectthereto. One such example computing module is shown in FIG. 9. Variousembodiments are described in terms of this example-computing module 900.After reading this description, it will become apparent to a personskilled in the relevant art how to implement the technology using othercomputing modules or architectures.

Referring now to FIG. 9, computing module 900 may represent, forexample, computing or processing capabilities found within desktop,laptop and notebook computers: hand-held computing devices (FDA's, smartphones, cell phones, palmtops, etc.); mainframes, supercomputers,workstations or servers; or any other type of special-purpose orgeneral-purpose computing devices as may be desirable or appropriate fora given application or environment. Computing module 900 might alsorepresent computing capabilities embedded within or otherwise availableto a given device. For example, a computing module might be found inother electronic devices such as, for example, digital cameras,navigation systems, cellular telephones, portable computing devices,modems, routers, WAPs, terminals and other electronic devices that mightinclude some form of processing capability.

Computing module 900 might include, for example, one or more processors,controllers, control modules, or other processing devices, such as aprocessor 904. Processor 904 might be implemented using ageneral-purpose or special-purpose processing engine such as, forexample, a microprocessor, controller, or other control logic. In theillustrated example, processor 904 is connected to a bus 902, althoughany communication medium can be used to facilitate interaction withother components of computing module 900 or to communicate externally.

Computing module 900 might also include one or more memory modules,simply referred to herein as main memory 908. For example, preferablyrandom access memory (RAM) or other dynamic memory, might he used forstoring information and instructions to be executed by processor 904.Main memory 908 might also be used for storing temporary variables orother intermediate information during execution of instructions to beexecuted by processor 904. Computing module 900 might likewise include aread only memory (“ROM”) or other static storage device coupled to bus902 for storing static information and instructions for processor 904.

The computing module 900 might also include one or more various forms ofinformation storage mechanism 910, which might include, for example, amedia drive 912 and a storage unit interface 920. The media drive 912might include a drive or other mechanism to support fixed or removablestorage media 914. For example, a hard disk drive, a floppy disk drive,a magnetic tape drive, an optical disk drive, a Cl) or DVD drive (R orRW), or other removable or fixed media drive might be provided.Accordingly, storage media 914 might include, for example, a hard disk,a floppy disk, magnetic tape, cartridge, optical disk, a CD or DVD, orother fixed or removable medium that is read by, written to or accessedby media drive 912. As these examples illustrate, the storage media 914can include a computer usable storage medium having stored thereincomputer software or data.

In alternative embodiments, information storage mechanism 910 mightinclude other similar instrumentalities for allowing computer programsor other instructions or data to be loaded into computing module 900.Such instrumentalities might include, for example, a fixed or removablestorage unit 922 and an interlace 920. Examples of such storage units922 and interfaces 920 can include a program cartridge and cartridgeinterface, a removable memory (for example, a flash memory or otherremovable memory module) and memory slot, a PCMCIA slot and card, andother fixed or removable storage units 922 and interfaces 920 that allowsoftware and data to be transferred from the storage unit 922 tocomputing module 900. Computing module 900 might also include acommunications interface 924.

Communications interface 924 might be used to allow software and data tobe transferred between computing module 900 and external devices.Examples of communications interface 924 might include a modem or softmodem, a network interface (such as an Ethernet, network interface card.WiMedia, IEEE 802.XX or other interface), a communications port (such asfor example, a USB port, IR port, RS232 port Bluetooth s interface, orother port), or other communications interface. Software and datatransferred via communications interface 924 might typically be carriedon signals, which can be electronic, electromagnetic (which includesoptical) or other signals capable of being exchanged by a givencommunications interface 924. These signals might be provided tocommunications interface 924 via a channel 928. This channel 928 mightcarry signals and might be implemented using a wired or wirelesscommunication medium. Some examples of a channel might include a phoneline, a cellular link, an RF link, an optical link, a network interface,a local or wide area network, and other wired or wireless communicationschannels.

In this document, the terms “computer program medium” and “computerusable medium” are used to generally refer to media such as, forexample, main memory 908, storage unit 920, storage media 914, andchannel 928. These and other various forms of computer program media orcomputer usable media may be involved in carrying one or more sequencesof one or more instructions to a processing device for execution. Suchinstructions embodied on the medium, are generally referred to as“computer program code” or a “computer program product” (which may begrouped in the form of computer programs or other groupings). Whenexecuted, such instructions might enable the computing module 900 toperform features or functions of the disclosed technology as discussedherein.

While various embodiments of the disclosed technology have beendescribed above, it should be understood that they have been presentedby way of example only, and not of limitation. Likewise, the variousdiagrams may depict an example architectural or other configuration forthe disclosed technology, which is done to aid in understanding thefeatures and functionality that can be included in the disclosedtechnology. The disclosed technology is not restricted to theillustrated example architectures or configurations, but the desiredfeatures can be implemented using a variety of alternative architecturesand configurations. Indeed, it will be apparent to one of skill in theart how alternative functional, logical or physical partitioning andconfigurations can be implemented to implement the desired features ofthe technology disclosed herein. Also, a multitude of differentconstituent module names other than those depicted herein can be appliedto the various partitions. Additionally, with regard to flow diagrams,operational descriptions and method claims, the order in which the stepsare presented herein shall not mandate that various embodiments beimplemented to perform the recited functionality in the same orderunless the context dictates otherwise.

Although the disclosed technology is described above in terms of variousexemplary embodiments and implementations, it should be understood thatthe various features, aspects and functionality described in one or moreof the individual embodiments arc not limited in their applicability tothe particular embodiment with which they are described, but instead canbe applied, alone or in various combinations, to one or more of theother embodiments of the disclosed technology, whether or not suchembodiments are described and whether or not such features are presentedas being a part of a described embodiment. Thus, the breadth and scopeof the technology disclosed herein should not be limited by any of theabove-described exemplary embodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional.” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time, but instead should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Likewise, wherethis document refers to technologies that would be apparent or known toone of ordinary skill in the art, such technologies encompass thoseapparent or known to the skilled artisan now or at any time in thefuture.

The presence of broadening words and phrases such as “one or more.” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. The use of theterm “module” does not imply that the components or functionalitydescribed or claimed as part of the module are all configured in acommon package. Indeed, any or all of the various components of amodule, whether control logic or other components, can be combined in asingle package or separately maintained and can further be distributedin multiple groupings or packages or across multiple locations.

Additionally, the various embodiments set forth herein arc described interms of exemplary block diagrams. Flow charts and other illustrations.As will become apparent to one of ordinary skill in the art afterreading this document, the illustrated embodiments and their variousalternatives can be implemented without confinement to the illustratedexamples. For example, block diagrams and their accompanying descriptionshould not be construed as mandating a particular architecture orconfiguration.

1-23. (canceled)
 24. A communication device comprising: at least onemodule operable to, at least: select a number of beacon phase cycles,between a minimum number of beacon phase cycles and a maximum number ofbeacon phase cycles, to perform in a beacon phase; and operate in alistening phase in which the at least one module, at least, searches fora beacon on a plurality of channels of the network.